He was arrested in April on suspicion of hacking mobile phones while employed by the paper.

Thurlbeck's involvement in the hacking affair has been under close scrutiny ever since details emerged of a crucial email headed "transcripts for Neville", which contained transcripts of messages illegally intercepted from the phone of PFA chief executive Gordon Taylor.

The email, which was sent in 2005 but only surfaced in April 2008, appeared to debunk News International's repeated assertion that hacking was only down to one "rogue reporter" at the News of the World.

Mahmood - the News Of The World's former investigations editor who is best known for disguising himself as a "fake sheikh" to carry out an undercover report on cricket match-fixing - is appearing at the Leveson inquiry this morning.

He now works for the Sunday Times and was behind the acclaimed News Of The World story that resulted in three Pakistan Test cricketers and a corrupt sports agent being sent to prison in November.